What do
the electrical terms voltage (measured in volts) and current (measured in
amperes, often shortened to amps) mean? Imagine the electric current flowing
in a conducting wire to be like cars travelling along a highway. The highway
is the wire and the voltage the speed at which the cars move. The current
corresponds to the number of cars passing a given point each second.

When a
current flows through a wire, electrical energy is converted into other
forms of energy, like heat in a heating element, light from the filament
of a bulb, or sound from a loudspeaker. The electric current could also
be made to produce mechanical energy, which is what happens in an electric
motor. A motor is therefore just a generator operating in reverse.